Journal American Rhododendron Society

Designing With Rhododendrons
Robert Stockmal
Shelton, Connecticut
Originally appeared in the "Rosebay", Massachusetts Chapter publication, revised by the author for publication in the Journal

Nothing can surpass the use of rhododendrons and azaleas in landscape design in the northeast, especially when the requirements are a no or low maintenance garden and year round lush evergreen appearance.
But before plant materials can be considered, the property's uses and spaces have to be planned. As the architect designs a building, the functions, spaces and then the traffic patterns have to be planned. Then the utilities and the mechanics of the project have to be justified before the materials are selected.
If your major space is a lawn, what is the purpose of that lawn? What are its uses? Is it strictly for viewing? What other outdoor spaces do you want and how are they going to relate to each other?
Next consider traffic flow. Is it convenient to go from one area to another and are the spaces divided nicely from each other? You ordinarily would not wish the picnic table located far from the kitchen. The vegetable garden ordinarily would not be the focal point of your view and the garbage cans and compost pile would not be very pleasant next to the patio.
After you organize your spaces, traffic flow and consider all the functions you wish to accommodate, you will want to consider the plant materials to enclose or separate those spaces. The use of small flowering trees and moderate growing rhododendrons is appropriate. Where a shrub mass opens from one space to another, you may want to punctuate that mass with one, or a cluster of flowering trees (e.g. Cornus kousa) and further emphasize that accent with a mass of semi-dwarf rhododendrons or evergreen azaleas.

Drawing by Robert Stockmal

A mass of dwarf rhododendrons against a background of larger growing ones can prove quite effective as an entrance planting. The use of individual shrubs or the mixing of different types of shrubs is not an effective way to use materials. I really think it is wasting your materials.

Drawing by Robert Stockmal

Many of my planting designs make use of masses of shrub materials, they often include rhododendrons and azaleas because of their unique properties. In such designs, I lean heavily on dwarf and semi-dwarf rhododendrons and low growing evergreen azaleas. Twenty or thirty R. 'Ramapo' with one or a cluster of three Cornus kousa are quite effective and make an outstanding outdoor wall or space divider.
Near a building or a house, unless the scale is enormous, I prefer to remain with the semi-dwarf and dwarf rhododendrons and azaleas. This sizing also applies to the use of other shrub materials. I use small growing flowering trees to soften the architecture and to tie the building to the upper story trees. One purpose of the trees is to unite the property and buildings with the surrounding environment. Major trees can be used to frame the building and to frame vistas.
Finding available rhododendrons or azaleas in quantities for mass plantings is a problem that often necessitates going to the grower. For many reasons that is not the most desirable procedure. The grower often is a wholesaler who will not sell to the retail trade. The wholesaler often does not grow plants on to desirable sizes. I would like to have in quantity and of good size, all the species, hybrids and cultivars listed in Greer's Guidebook.
The rhododendrons I find most useful for broad and deep mass planting include many of the small leaf and dwarf varieties. R. 'Laetevirens', R. 'Laurel Pink', R. 'Moerheim', R. mucronulatum / R. mucronulatum dwarf, R. mucronulatum 'Cornell Pink', R. 'Pink Drift', R. 'Purple Gem', R. 'Ramapo', R. 'Starry Night', R. 'Tiffany' and R. 'Waltham' are hardy enough in Connecticut and in New York State.
For more structure, or greater height, or in a border, I find the following more appropriate: R. 'Boule de Neige', R. 'Chionoides', R. 'Dora Amateis', R. 'Janet Blair', and in protected areas R. 'Mary Fleming'.
For massive backgrounds I use R. 'Scintillation', R. carolinianum, R. 'English Roseum', R. 'Cunningham's White', or Kalmia latifolia, and in very large spaces, R. maximum.
There are many dwarf and evergreen azaleas that are useful for broad mass plantings, covering banks and for under planting small flowering trees. My favorites are 'Blaauw's Pink', 'Delaware Valley White', 'Greeting', 'Girard's Hot Shot', 'Kaempo', 'Poukhanense Pink', 'Rosebud', 'Stewartstonian', 'Tradition', 'Flame Creeper', 'Itsigishi', 'Mount Seven Star', R. nakaharae, and many of the Polly Hill hybrids including 'Alexander', 'Joseph Hill', 'Jeff Hill', 'Late Love', and 'Wintergreen'.

Drawing by Robert Stockmal

On the opposite side of a pond, on the bank, many of the Ghent and Exbury hybrids are quite effective. At our large pond, I used 'Gibraltar', 'Brazil' and 'Pumpkin'.
To emphasize my previous statement, you can design a better landscape by using groups or masses of the same cultivars, the same textures and colors, off-setting those materials with an accent in the form of a small tree or a sculpture.

Robert Stockmal, a member of the Connecticut' Chapter, is a landscape architect practicing in Shelton, Connecticut.